The present invention relates to medical procedures in which an invasive device such as a catheter, guide wire, biopsy needle, endoscope, laparoscope or the like is inserted into a body, and more particularly concerns the tracking of such a device, in three dimensions on multiple display screens, without the use of X-rays.
X-ray fluoroscopes are used routinely to monitor the placement of invasive devices during diagnostic and therapeutic medical procedures. Conventional X-ray fluoroscopes are designed to minimize X-ray dosage. Nevertheless, some procedures can be very long and the accumulated X-ray dose to the patient can become significant. The long term exposure of the attending medical staff is of even greater concern since they participate in these procedures regularly. Consequently, it is desirable to reduce the X-ray dose during these procedures.
One consequence on the need to minimize x-ray dose is the use of minimal fields-of-view. Smaller fields-of-view necessitate the frequent movement of the X-ray detection system or of the patient to follow the invasive devices during a procedure. Automatic registration of the invasive device within the field-of-view of the imaging system may shorten the procedure and reduce the number of attending personnel needed to perform the procedure.
Another limitation on the use of X-ray fluoroscopes is that the technique is projective in nature and produces a single two-dimensional image. Information concerning the depth of an object within the field-of-view is not available to the operator. It is often desirable to obtain this information during invasive procedures. Bi-planar X-ray fluoroscopes utilizing dual X-ray beams have been devised for this purpose. Dual beam X-ray systems, however, double the X-ray dose to the subject and are more complicated.